Re: [PATCH 0/2] qla2xxx: fix errors in PCI device remove with ongoing I/O

["Madhani, Himanshu" <Himanshu.Madhani@cavium.com>]

On 11/7/16, 11:53 AM, "Mauricio Faria de Oliveira" <mauricfo@linux.vnet.ibm.com> wrote:

>This patchset addresses a couple of errors that might happen during
>PCI device remove (e.g., PCI hotplug, PowerVM DLPAR), which prevent
>the successful removal and re-addition of the adapter to the system,
>and cause an oops and/or invalid DMA access (triggers an EEH event).
>
>It allowed several cycles of PCI device add/remove with ongoing I/O,
>to complete successfully without triggering oopses or EEH events.
>
>Verified on v4.9-rc3.
>
>Test-case:
>---
>    # lspci
>    <...>
>    001d:70:00.0 Fibre Channel: QLogic Corp. ISP2532-based ...
>    001d:70:00.1 Fibre Channel: QLogic Corp. ISP2532-based ...
>    <...>
>
>    # for sd in $(find /sys/bus/pci/devices/001d:70:00.*/ \
>                       -name 'sd*' -printf "%f\n"); do \
>        dd if=/dev/$sd of=/dev/null iflag=nocache & done
>
>    # echo 1 | tee /sys/bus/pci/devices/001d:70:00.*/remove
>    (this either works or not)
>
>    # echo 1 > /sys/bus/pci/rescan
>
>Before:
>---
>    <...>
>    EEH: Frozen PHB#1d-PE#700000 detected
>    qla2xxx [001d:70:00.1]-8042:2: PCI/Register disconnect, exiting.
>    <...>
>    EEH: Detected PCI bus error on PHB#29-PE#700000
>    <...>
>    (and/or)
>    Unable to handle kernel paging request for data at address 0x00000138
>    <...>
>    NIP [d000000004700a40] qla2xxx_queuecommand+0x80/0x3f0 [qla2xxx]
>    LR [d000000004700a10] qla2xxx_queuecommand+0x50/0x3f0 [qla2xxx]
>
>    (command does not return; adapter cannot be re-added)
>
>After:
>---
>    <...>
>    qla2xxx [001d:70:00.0]-801c:1: Abort command issued nexus=1:0:0 --  1 2003.
>    <...>
>    qla2xxx [001d:70:00.1]-801c:2: Abort command issued nexus=2:3:0 --  1 2003.
>    <...>
>
>    (command does return; adapter can be re-added correctly)
>
>
>Mauricio Faria de Oliveira (2):
>  qla2xxx: do not queue commands when unloading
>  qla2xxx: fix invalid DMA access after command aborts in PCI device
>    remove
>
> drivers/scsi/qla2xxx/qla_os.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
>-- 
>1.8.3.1
>
Thanks for the patches. Series Looks Good. 

Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>

>